Table 1 Characteristics of patients with EOCC in the right-side and left-side group

n

1980

3035

Sex

 < 0.001^*

 Female

907(45.8%)

1587(52.3%)

 Male

1073(54.2%)

1448(47.7)

Histology

 < 0.001^*

 Non-specific adenocarcinoma

1680(84.8%)

2847(93.8%)

 Specific adenocarcinoma

294(14.8%)

184(6.1%)

 Other

6(0.3%)

4(0.1%)

Pathologic stage

0.002^*

 Stage I-II

807(40.8%)

1105 (36.4%)

 Stage III-IV

1173 (59.2%)

1930(63.6%)

Surgery of Primary Site

0.006^*

 Yes

1965 (99.2%)

2985(98.4%)

 No

15(0.8%)

50(1.6%)

Reginal lymph node dissection

 < 0.001^*

 Yes

1937(97.8%)

2904 (95.7%)

 No

43(2.2%)

131 (4.3%)

Radiation

0.006^*

 Yes

51(2.6%)

122(4.0%)

 No

1929(97.4)

2913(96.0%)

Chemotherapy

 < 0.001^*

 Yes

1217(61.5%)

2053(67.6%)

 No/unknown

763(38.5%)

982(32.4%)

Bone metastasis

0.146

 Yes

6(0.3%)

18(0.6%)

 No

1974(99.7%)

3017(99.4%)

Brain metastasis

0.071

 Yes

0(0%)

5 (0.2%)

 No

1980(100%)

3030(99.8%)

Liver metastasis

0.002^*

 Yes

298(15.1%)

561(18.5%)

 No

1682(84.9%)

2474(81.5%)

Lung metastasis

0.320

 Yes

59(3.0%)

106 (3.5%)

 No

1921 (97.0%)

2929 (96.5%)

Grade

 < 0.001^*

 Well and moderate

1495(75.5%)

2564(84.5%)

 Poor

485(24.5%)

471(15.5%)

Pretreatment CEA level

0.061

 Negative

1190(60.1%)

1743(57.4%)

 Elevated

790(39.9%)

1292(42.6%)

Perineural invasion

 < 0.001^*

 Yes

305(15.4%)

603(19.9%)

 No

1675(84.6%)

2432(80.1%)

Tumor size

 < 0.001^*

 Median

55.00

45.00

OS month

0.002^*

 Median

52.00

54.00